What do we really mean by tank size?

[js302]

Picture a large (9in) Oscar in a 75 gal tank with internal filters.
It would suffice to say that at his metabolic disposal, he has 75 gallons of water from which to derive oxygen, expel co2 and secrete nitrogenous waste.

In this way we mean to say that tank size describes the volume of water in his system.

Now, imagine the same fish in a 180 gal but confined, perhaps by plastic mesh to a space the size of a 75 gallon tank. Is this fish in a 180 or in a 75?
If it is the case that he is in a 75, tank size does not describe the volume of water available to him but in fact to his physical confines. If it can be said that he is in a 180, ‘tank size’ still describes the volume of water in his system.

If we say that a particular species individual needs a 75 gal tank, do we mean this in terms of water availability, or do we mean it in terms of his physical (and perhaps mental) freedom.

Again imagine an aro in a 75 but with a large and effective sump and filtration unit meaning that this aro is exposed to perhaps 150 gallons of water. We might see such an aro in a restaurant.
Does this aro really reside in a 75 gallon tank? Really?

So when we talk about ‘tank size’, are we referring to physical constraint or do we refer to available water for his biological wellbeing? In terms of rate of increase of nitrate concentration, in a large system, despite a small tank, increase in nitrate concentration would be lower than in a system composed solely of water contained in the tank the fish lives in.

What are you guys and girl’s thoughts on this?

 

[islander671]

Very interesting idea, had never thought of that before. Personally i would think that both factors play a role in how well a fish will do. But would think that the water available to the fish would stand as the more important of the two. Without going to extremes anyway such as 10g t swim in and 200g total water. I just see it as being stuck in a small room (prison cell) for life, or on an island. you can survive (although maybe not happy) as long as the conditions are right. regardless of how much room you have.

 

[HunterX]

wow... your question almost borders on the metaphysical...
tough one... I'll have to ponder it a bit.

 

[js302]

Personally i would think that both factors play a role in how well a fish will do. But would think that the water available to the fish would stand as the more important of the two. Without going to extremes anyway such as 10g t swim in and 200g total water. I just see it as being stuck in a small room (prison cell) for life, or on an island. you can survive (although maybe not happy) as long as the conditions are right. regardless of how much room you have.

Yes!
We talk (quite rightly so) about the difference between survive and thrive. In such a 'prison cell', can breeding condition, large size, great colouration, and above all excellent health be achieved? I think so!
Do you guys feel that in a system where physical constraint is apparent, a fish can thrive?

 

[Villimadur]

A big fish in a small container will be stressed, even if it has pristine water conditions all the time, and stress will manifest in a number of diffrent ways that could affect size, color, health and/or breeding. It will survive, but not thrive in most cases.
Best example would be the diffrent sizes of the fish raised from the same spawn, in diffrent sized aquariums.

You can get away with alot of things when breeding, but it will affect the outcome in some way.

 

[Bderick67]

I would think most logical people would look to tank size as physical restraints. As to how you provide the fish with proper water parameters, well sure more water may mean stable water conditions but why have a small tank with a large sump? The fish would do much better in a large tank and smaller sump.

I got an idea, how about putting the same said oscar in a 10 gallon tank with a 300 gallon sump. Now that is gonna be some prisitine water right?

 

[danny]

I would think most logical people would look to tank size as physical restraints. As to how you provide the fish with proper water parameters, well sure more water may mean stable water conditions but why have a small tank with a large sump? The fish would do much better in a large tank and smaller sump.

I got an idea, how about putting the same said oscar in a 10 gallon tank with a 300 gallon sump. Now that is gonna be some prisitine water right?

i see what you are saying but put the oscar in a 300and a 10 gal sump not much room for bio,,,,,just adding food for thoutht

 

[danny]

have you seen the thread on over stocked tanks???

 

[greenterra]

I prefer to go by footprint or actuall measurment.Take your standard 5gal.correct me if I am wrong but from what I have seen,In the USA a std 55 is only 12" in width(front to back).Yet here in Aus a std 55 is 48" x 15" x 18" .Mush more useable IMO.Physical room is how I see it so long as sufficient filtration and water quality is met.

 

[Villimadur]

i see what you are saying but put the oscar in a 300and a 10 gal sump not much room for bio,,,,,just adding food for thoutht

Other way around 10 gal tank, but 300 gal sump.
But I fear neither would allow the fish to thrive, if it allows it to survive at all.
On one hand you have crystal clear water and no bad stuff to be found for miles, but your fish is effectively in a stretchcoat.
The other hand would work for a limited time, and the stress on the fish would increase with time as the tank becomes a cespool.

A split down the middle might be a good compromise, or a 70/30 distribution of the gallonage.

But back on topic, tank size should be measured by the amount of room the fish has for movement. If you put a divider in a 300 gal, you are effectively creating two joined tanks, and thus changing the amount of room available for fish to do their fishy stuff.